Similar to Oh Crap, though the difference lies in that Oh Crap moments involve a single moment where the character finds that they are screwed, while Villainous Breakdowns have them see it coming from miles away. The good-guy counterpart is the Heroic BSOD.

Note that this isn't necessarily an example of Villain Decay. On the contrary, some villains become much more terrifying and dangerous when their façade of cunning and civility crumbles. They might even end up dishing out a vicious No-Holds-Barred Beatdown to the Hero(s), engage in some Cold-Blooded Torture or, goodness forbid, drop the Villain Ball and Just FINISH HIM Already instead of playing around. It could even lead them to stop holding back their true nature and assuming their true form as the monster they actually were. Affably Evil and Faux Affably Evil villains are prone to becoming far more terrifying and disturbing when they undergo one of these because their fairly normal personality serve to emphasize their breakdown.

A somewhat less common, but not exactly infrequent, form of breakdown results in the exact opposite reaction: the villain lapses into a catatonic state as the shock of their defeat robs them of their wits. Another form of breakdown occurs due to Heel Realization causing a Villainous BSOD. Yet another is the impotent flailing of a defeated villain, left with nothing without power.

The scale of the breakdown generally depends on the nature—and overall impressiveness—of the villain. A Smug Snake, being generally inclined to rate their own abilities higher than everyone around them anyway and less equipped to deal with setbacks, will usually break down more frequently and over relatively minor spanners in the works, with the resulting tantrum using being less-than-impressive. A Magnificent Bastard, on the other hand, is already the type of villain who's not inclined to sweat the small stuff, and will usually respond to most setbacks fairly calmly; however, this merely means that if their plans suffer a particularly impressive implosion, then this will usually make their resulting breakdown all the more epic. Similarly, a relatively minor or small-scale villain may have a breakdown on the level of a temper tantrum or explosive Cluster F-Bomb rant; a major or larger scale villain, however, will frequently have a breakdown with potentially (and quite literally) world-ending consequences. As the old saying goes, "The bigger you are, the harder you fall".

In another type, the breakdown won't be one, sudden explosion, but a gradual progression of smaller, gradually increasing breakdowns happening over the course of the story. As their plan comes closer to failing or their plans fail again and again, they simply get worse and worse as the breakdown continues, until finally, they lose it completely. This normally happens in the buildup to the final confrontation. This can overlap with Sanity Slippage, where a character gradually becomes more and more insane as time goes on. And as a special treat, when the villain finally goes so crazy and bat-shit insane that he completely loses it, other characters tend to hit him with a You're Insane!.

Another type of breakdown is when the villain becomes extremely furious when either something happens that isn't part of his plan or his plans end up being ruined, or both. Once pissed off, he may lose his temper and say such phrases as "Why Won't You Die?", "I've had it with you!", "You Bastard!", or even "This Is Unforgivable!!". Either way, the villain will scream more and more at the other characters in fury before being bested by them.

This is not the case for all villains, as some can manage to never have this breakdown, which can be played in two ways. Firstly, the villain is a Villain Sue who gets a Karma Houdini and never suffers a loss; secondly, played more for horror, the villain manages to keep his cool even as he's losing making him/her seem more horrifying and intimidating to the heroes.

Note that this is usually done in a climax and just the fact that one occurs is a pretty big spoiler, so read with caution.